Your daily cup of coffee or tea may be doing more than boosting alertness. A major long-term study published in Journal of the American Medical Association and funded by the National Institutes of Health suggests that moderate caffeine consumption could significantly reduce the risk of dementia.
Researchers tracked participants for up to 43 years through two landmark cohort studies:
Nurses’ Health Study
Health Professionals Follow-up Study
Participants, typically in their mid-40s or early 50s at the start, regularly reported their dietary habits and lifestyle patterns. Over time, 11,033 individuals developed dementia, confirmed through medical diagnosis or death records.
The findings were clear:
People who drankone to five cups of caffeinated coffee dailyhad about a20% lower risk of dementiacompared to those who consumed almost none.
Those who drankat least one cup of caffeinated tea dailysaw roughly a15% reduction in risk.
The strongest benefits were observed attwo to three cups of coffeeorone to two cups of tea daily.
Interestingly, the protective association disappeared among those who consumed decaffeinated coffee. Regular coffee contains around 80–100 mg of caffeine per cup, while decaf contains just 2–7 mg — a difference researchers believe may be crucial.
Coffee and tea are rich in bioactive compounds such as polyphenols and caffeine. These substances are linked to:
Reduced inflammation
Protection against cellular damage
Improved vascular health
All of these factors play roles in cognitive decline.
While previous studies produced mixed results, many lacked long follow-up periods. The strength of this research lies in its four-decade data span and consistent dietary tracking.
According to the World Health Organisation, an estimated 5.7 crore people worldwide were living with dementia in 2021 — a number expected to rise sharply as populations age.
The study also found that the protective link held even among individuals genetically predisposed to Alzheimer’s disease and other forms of cognitive decline.
The findings align with broader evidence linking moderate coffee consumption (two to five cups daily) to:
Longer lifespan
Lower risk of type 2 diabetes
Reduced cardiovascular disease risk
Improved liver health
Lower Parkinson’s risk
Importantly, higher intake did not show clear harm in this study, although moderation remains key.
For millions who rely on their daily brew, the message is encouraging. Moderate caffeine intake — especially from coffee and tea — may help protect cognitive health over the long term.
While more research is needed to fully understand the mechanisms, your morning cup may be doing more than waking you up — it could be helping safeguard your brain for decades.
